[KERNEL] Power over OTG host mod. - ONE Android Development

[From my README]
A mod for the Oneplus One DWC3 otg module. This allows for charging and host mode simultaneously, inspired by Ziddey's msm_otg mod for the Nexus 4/7 (2013). Functionality was ported over from his kernel hack to the DWC3 USB driver which now handles the MSM8974 USB controller.
The hack works through setting a custom module parameter I've added to allow 'ACA' host mode. This flag effectively turns on ID_A host mode while disabling VBUS power going to the hosted device. I've uploaded the modded dwc3_otg.c file that you can replace in your Oneplus One(bacon) kernel source of choice. It'll be located in the drivers/usb/dwc3/ directory. I've also uploaded my personal kernel image with this hack built on top of Franco's kernel. It also has other modules built into it, mainly DRM/Devtmpfs/Cifs/NFS/NTFS/Alsa Sequencer/Usbip/Binfmt/loadable modules/etc... It was compiled with GCC 4.9 NDK version.
Usage: First you'll need either a generic Y split USB OTG cable or a powered USB hub connected to regular OTG(I've only tested the Y cable).
With the modified kernel flashed, open a terminal shell and as root, enter the following command: "echo Y > /sys/module/dwc3/parameters/aca_enable"
This activates the 'ACA' host mode hack.
[UPDATE]
Wiggling the cord is not needed anymore. I've updated the code so that the phone automatically accepts a charge on entering host mode.
The tricky part is now getting your Y-OTG adapter to send power to the phone. First with power cable and USB device(s) connected the adapter, plug the Y cable into the phone. Test that the phone reads the device. Now, unplug the cable from the phone, leaving the USB device and power cord plugged into the OTG adapter. Gently wiggle the cable slightly while slowly pushing it back into the phone's port, wait for the charge indicator to come on. Once the phone detects the charge, you can push the cable in all the way. The phone should be charging at max current rate while retaining host mode.
Please, if you can test the powered hub method or have improvements to this hack, feel free to share! Also, the standard legal disclaimer applies here that by using this mod/code/kernel in anyway is completely your responsibility. I'm not liable for any possible damages to your devices.
Links:
DWC3 OTG Modification For OnePlus One
https://github.com/sollapse/opo_dwc3_otg/
Ziddey's Original ACA hack for Mako
https://github.com/ziddey/mako/commits/nightlies-4.3-JSS
Franco's Oneplus One Kernel Source
https://github.com/franciscofranco/one_plus_one

---

Hi sollapse, thank you a lot for this patch, i modified it a little for my xperia z2, it seems to be working just fine, it detects when power is disconnected and switches back to OTG_STATE_A_IDLE automatically, anyway, the only thing that i couldnt get to work is once it is on host mode, when i connect the power it doesnt start charging, perhaps you can find a way to get it working, here's my patch:
Code:
--- dwc3_otg.c 2015-09-22 14:44:45.115324661 -0300
+++ dwc3_otg.c.new 2015-09-22 14:47:40.950239287 -0300
@@ -45,6 +45,12 @@ static void dwc3_otg_reset(struct dwc3_o
static void dwc3_otg_notify_host_mode(struct usb_otg *otg, int host_mode);
static void dwc3_otg_reset(struct dwc3_otg *dotg);
+/*OTG charging hack*/
+static bool aca_enable = 0;
+static bool enable_otg_charge = 0;
+module_param(enable_otg_charge, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(enable_otg_charge, "Force ACA host mode to allow charging and host.");
+
/**
* dwc3_otg_set_host_regs - reset dwc3 otg registers to host operation.
*
@@ -204,41 +210,45 @@ static int dwc3_otg_start_host(struct us
if (!dwc->xhci)
return -EINVAL;
-
- if (!dotg->vbus_otg) {
- dotg->vbus_otg = devm_regulator_get(dwc->dev->parent,
- "vbus_dwc3");
- if (IS_ERR(dotg->vbus_otg)) {
- dev_err(dwc->dev, "Failed to get vbus regulator\n");
- ret = PTR_ERR(dotg->vbus_otg);
- dotg->vbus_otg = 0;
- return ret;
- }
- }
-
+
+ if(!aca_enable){
+ if (!dotg->vbus_otg) {
+ dotg->vbus_otg = devm_regulator_get(dwc->dev->parent,
+ "vbus_dwc3");
+ if (IS_ERR(dotg->vbus_otg)) {
+ dev_err(dwc->dev, "Failed to get vbus regulator\n");
+ ret = PTR_ERR(dotg->vbus_otg);
+ dotg->vbus_otg = 0;
+ return ret;
+ }
+ }
+ }
+
if (on) {
dev_dbg(otg->phy->dev, "%s: turn on host\n", __func__);
dwc3_otg_notify_host_mode(otg, on);
-
- /* register ocp notification */
- if (ext_xceiv && ext_xceiv->otg_capability &&
- ext_xceiv->ext_ocp_notification.notify) {
- ret = regulator_register_ocp_notification(
- dotg->vbus_otg,
- &ext_xceiv->ext_ocp_notification);
- if (ret)
- dev_err(otg->phy->dev,
- "unable to register ocp\n");
- }
-
- ret = regulator_enable(dotg->vbus_otg);
- if (ret) {
- dev_err(otg->phy->dev, "unable to enable vbus_otg\n");
- dwc3_otg_notify_host_mode(otg, 0);
- return ret;
- }
-
+
+ if(!aca_enable){
+ /* register ocp notification */
+ if (ext_xceiv && ext_xceiv->otg_capability &&
+ ext_xceiv->ext_ocp_notification.notify) {
+ ret = regulator_register_ocp_notification(
+ dotg->vbus_otg,
+ &ext_xceiv->ext_ocp_notification);
+ if (ret)
+ dev_err(otg->phy->dev,
+ "unable to register ocp\n");
+ }
+
+ ret = regulator_enable(dotg->vbus_otg);
+ if (ret) {
+ dev_err(otg->phy->dev, "unable to enable vbus_otg\n");
+ dwc3_otg_notify_host_mode(otg, 0);
+ return ret;
+ }
+ }
+
/* The delay between enabling regulator and adding the
platform device is needed to succeed in the enumeration
for certain devices. */
@@ -269,7 +279,9 @@ static int dwc3_otg_start_host(struct us
dev_err(otg->phy->dev,
"%s: failed to add XHCI pdev ret=%d\n",
__func__, ret);
- regulator_disable(dotg->vbus_otg);
+ if(!aca_enable)
+ regulator_disable(dotg->vbus_otg);
+
dwc3_otg_notify_host_mode(otg, 0);
return ret;
}
@@ -279,24 +291,27 @@ static int dwc3_otg_start_host(struct us
dwc3_otg_reset(dotg);
} else {
dev_dbg(otg->phy->dev, "%s: turn off host\n", __func__);
-
- ret = regulator_disable(dotg->vbus_otg);
- if (ret) {
- dev_err(otg->phy->dev, "unable to disable vbus_otg\n");
- return ret;
- }
-
- /* unregister ocp notification */
- if (ext_xceiv && ext_xceiv->otg_capability &&
- ext_xceiv->ext_ocp_notification.notify) {
- ret = regulator_register_ocp_notification(
- dotg->vbus_otg, NULL);
- if (ret)
- dev_err(otg->phy->dev,
- "unable to unregister ocp\n");
- }
-
- dwc3_otg_notify_host_mode(otg, on);
+
+ if(!aca_enable){
+ ret = regulator_disable(dotg->vbus_otg);
+ if (ret) {
+ dev_err(otg->phy->dev, "unable to disable vbus_otg\n");
+ return ret;
+ }
+
+ /* unregister ocp notification */
+ if (ext_xceiv && ext_xceiv->otg_capability &&
+ ext_xceiv->ext_ocp_notification.notify) {
+ ret = regulator_register_ocp_notification(
+ dotg->vbus_otg, NULL);
+ if (ret)
+ dev_err(otg->phy->dev,
+ "unable to unregister ocp\n");
+ }
+ }
+
+ if(!aca_enable)
+ dwc3_otg_notify_host_mode(otg, on);
platform_device_del(dwc->xhci);
/*
@@ -341,8 +356,11 @@ static int dwc3_otg_set_host(struct usb_
* required for XHCI controller before setting OTG Port Power
* TODO: Tune this delay
*/
- msleep(300);
- dwc3_otg_set_host_power(dotg);
+
+ msleep(300);
+ if(!aca_enable){
+ dwc3_otg_set_host_power(dotg);
+ }
} else {
otg->host = NULL;
}
@@ -972,7 +990,17 @@ static void dwc3_otg_sm_work(struct work
dev_dbg(phy->dev, "vbus_drop_det\n");
/* staying on here until exit from A-Device */
} else {
- phy->state = OTG_STATE_A_HOST;
+ //if we have power and enable_otg_charge, force charging on
+ if (test_bit(B_SESS_VLD, &dotg->inputs) && enable_otg_charge){
+ if(charger){
+ dev_info(phy->dev, "OTG charging is ON!!!\n");
+ aca_enable = 1;
+ charger->chg_type =DWC3_SDP_CHARGER;
+ dwc3_otg_set_power(phy, DWC3_IDEV_CHG_MAX);
+ }
+ } else
+ aca_enable = 0;
+ phy->state = OTG_STATE_A_HOST;
ret = dwc3_otg_start_host(&dotg->otg, 1);
if ((ret == -EPROBE_DEFER) &&
dotg->vbus_retry_count < 3) {
@@ -1000,7 +1028,15 @@ static void dwc3_otg_sm_work(struct work
break;
case OTG_STATE_A_HOST:
- if (test_bit(ID, &dotg->inputs)) {
+ if (enable_otg_charge){
+ //detect power change and switch back to OTG_STATE_A_IDLE
+ if(!test_bit(B_SESS_VLD, &dotg->inputs)){
+ dev_info(phy->dev, "Power disconnected, charging disabled!!!\n");
+ dwc3_otg_start_host(&dotg->otg, 0);
+ phy->state = OTG_STATE_A_IDLE;
+ work = 1;
+ }
+ } else if (test_bit(ID, &dotg->inputs)) {
dev_dbg(phy->dev, "id\n");
dwc3_otg_start_host(&dotg->otg, 0);
phy->state = OTG_STATE_B_IDLE;

---

I've updated my code a couple of days ago to automatically apply power during the state change, assuming a charger is connected to the y cable (USB devices would not power otherwise). In your mod, it seems you're attempting to detect a charge using the 'B' mode state, but by that time with the aca flag enabled, the USB controller should be in ID_A host mode instead of B_SESS_VLD. The driver's 'set_power' function already checks the line for current automatically. Please look at the updated code to see what I did during the state change. It should all work utilizing the one parameter flag.

---

I tested this with a patched sultanXDA CAF kernel (since the .c source file was slightly different, I was careful to only merge the relevant changes), and a powered USB HUB. It works perfectly! Thanks.

---

Phoenix Wright said:
I tested this with a patched sultanXDA CAF kernel (since the .c source file was slightly different, I was careful to only merge the relevant changes), and a powered USB HUB. It works perfectly! Thanks.
Click to expand...
Click to collapse
That's great! I'm pretty certain with the push to USB Type C and potential USB 3.1 support, that the DWC3 driver will be used across most devices for now on. This code should merge well with them if ACA is absent (Zenphone 2 is the only exception I've found so far since Intel enabled it in the driver).

---

Can someone post a modded CAF kernel for the opo? I am having issues building a kernel as I currently only have a windows box.

---

snekiam said:
Can someone post a modded CAF kernel for the opo? I am having issues building a kernel as I currently only have a windows box.
Click to expand...
Click to collapse
Latest Sultanxda kernel (as of 10/4), with the CAF dwc_otg modified with sollapse's patches. His sources are here: https://github.com/sultanxda/android_kernel_oneplus_msm8974
I used Google GCC 4.8, which is the same one he uses, as far as I could tell.
View attachment sultan10-4_otg-y.7z
@sollapse I noticed a bug. I made two widgets with an app on Play Store (to enable and disable this hack). I disabled this by mistake while the OTG device and charge were still inserted, and after I removed them I got a kernel panic, could this be fixed?

---

I should be able to fix it. I'll look at it again and will try to clean up the state change code.

---

Kernel
Can someone please upload a kernel .img?
I am not able to compile a kernel on my own....

---

@sollapse I fixed the kernel panics, and also another bug (when the aca_enable parameter was on, you couldn't charge at full speed with a wall charger - not in host mode, just simple charging). I've done all possible status changes (set aca_enable to on, insert otg-y cable + device, turn aca_enable off, unplug device; aca_enable is off, plug regular otg cable + device, turn aca_enable on, unplug device, set aca_enable to off, re-plug). These two situations respectively gave these results: kernel panic and inability to use regular otg again.
Turns out that the issues were with "regulator_disable", now it's executed when the regulator is enabled, regardless of the aca_enable parameter.

---

Another fix for incorrect usage: if you connected a regular OTG cable+device while aca_enable was set to Y, it would show the charging icon, and it would even stay there after the device was disconnected! Sadly I can't prevent the charging icon from appearing (as this hack basically forces all the "unknown" chargers to be reported as USB - as opposed to AC - chargers... and the weird part is that the charge coming from OTG-Y is an "unknown charger"... but the charge (?) coming from a regular OTG device is an "unknown charger" too! XD, if there's a way it's out of reach for me), but I managed to make it go away after disconnection. Basically, it doesn't force "unknown" to USB if the function gets called to *disable* charging. I guess this is the best I can do for this kernel mod ^_^

---

It looks I was wrong, after lots of debugging of dwc3_otg I learned how it works, so I overhauled the patch. It works more cleanly now: it actually properly detects the charger (no more phantom notifications, faster charging rates if it's allowed by the charger), supports unplugging and replugging of the power cord while using OTG-Y, and unplugging of the device after power was unplugged, fixes all sorts of race conditions and wrong usages of the aca_enable parameter (I'm not sure if it's all of them, but I've been testing and fixing things for a while).
I attach a .diff for CAF kernels. Take note that to use the fix for plugging OTG devices in sleep mode you need to patch the charger driver: https://github.com/sultanxda/androi...mmit/7b023b295fdfa4789c93aee8b04f5d2a9b52dbba

---

Wow, I've completely abandoned this hack since it's worked well enough for me . Also haven't had much time due to work and other necessities. Thanks for the patches @Phoenix Wright for cleaning up this hack! This should be a standard addition to all future Android kernels.

---

sollapse said:
Wow, I've completely abandoned this hack since it's worked well enough for me . Also haven't had much time due to work and other necessities. Thanks for the patches @Phoenix Wright for cleaning up this hack! This should be a standard addition to all future Android kernels.
Click to expand...
Click to collapse
Yeah, I wonder why they haven't implemented the feature officially, as it can be done just fine
And many thanks for developing this
By the way, I realized the reboots when inserting an OTG-Y device in deep sleep were not actually fixed, as I got a reboot yesterday, my bad (sultanxda fixed the issues with doing it with regular OTG, but it seems the issue with OTG-Y was different). It seems it's fixed properly this time though. Same patch as yesterday, just a two line difference.

---

Thanks for the original mod, sollapse, and thanks for your patches and all the updates, Phoenix. Just to confirm: this mod requires that on every kernel update via Sultan's OTA, the kernel source be pulled, patched, flashed onto your OPO, and finally activated using the aca command?
I'm off to go learn how to build a kernel from this handy guide, if anyone else is interested in jumping on this exciting bandwagon.
http://forum.xda-developers.com/android/software/ultimate-guide-compile-android-kernel-t2871276
EDIT: Thought I'd keep everyone abrest of my progress as a total newbie trying this out. I've used Ubunutu before, but had a lot of headaches trying to get my network working properly.
5:00pm: started the downloads of Ubuntu and Virtualbox. I have Hyper-V support (which is supposedly faster) on my desktop rig, but it has network issues, so I went with Virtualbox. Apparently, one of the things needed to create a kernel is a "toolchain". The guide uses "arm-eabi-4.33", but Phoenix and apparently sultan use gcc 4.8, so we'll go with that. But, how do I replace them? Can I just switch the git urls with this one I found of Google's toolchain?
5:30pm: got Ubuntu's 15.10 iso downloaded and VirtualBox installed. We'll figure out the toolchains later.
5:45pm: OK, Ubuntu is installing. I did the default on everything (2GB RAM, 8GB virtual hard disk). Booted up, installed it, and rebooted. "SQUASHFS errors" on first Ubuntu boot. The issues begin early, lol.
5:50pm: Checked the iso's MD5, matches up. Google'd around, but only random fixes that don't really fit (updating my BIOS? on a virtualbox?!). OK, let's try again with 3GB of RAM (my rig has 8GB) and 12GB of disk space.
5:55pm: "SquashFS errors" again. Whhhhhhhyyyy, Ubuntu, whyyyyyyyyy.
5:56pm: Hmm, what if I just shut down the virtual box and just try starting Ubuntu again?
5:57pm: HOLYCOWITWORKED. Thank you, Ubuntu--I love you.
5:58pm: Why is the resolution so small even though Ubuntu is installed? Everything is huge and my mouse is a little laggy.
6:05pm: OK, from a StackExchange post: you need "Guest Additions" to change the resolution. In the VirtualBox window (not in Ubuntu), you just click "Install Guest Additions" and it does its thing. It actually inserts the files as a virtual CD, haha. That's neat.
6:15pm: Trying to get the hang of "Right Control" as "host key". But, wait, why can't I copy/paste between my host and guest (copying all the commands from the guide linked above)? I feel like I had that last time I used VirtualBox. The Firefox in Ubunutu is really slow, too, and troubleshooting is mostly through Google right now, lol, and I don't want slow troubleshooting.
6:20pm: Oh, bidirectional copy/paste needs to be enabled. I see....
6:22pm: I FEEL LIKE A GOD NOW. I can copy and paste between TWO operating systems running my PC. WOWZA....I don't know what enromous amount of engineering that required, but it is a killer feature.
6:26pm: I'm trying to learn all the commands that the guide is using, just in case I mess up somewhere. What does the "-y" do in apt-get?
6:26:15pm: Thank you, random internet stranger many years ago, about telling me what a "man page" is. It's a simple website/HTML document that will actually explain all the arguments of a command. Great in interpreting the exotic arguments of cerebral StackExchange users....and what "-y" does in apt-get....
6:26:30pm: "-y" just hits "yes" to any prompts or whatever that apt-get invokes. Nice noob feature for people like me, haha. All right, I'm OK with that argument, let's do it!
6:30pm: Next, "mkdir"....well, that makes sense. But, where is it making this folder? How does it know where to put it????
6:33pm: Ah, so there is a "Home" folder that is the default folder. That's where it puts things. I made like 15 folders using "mkdir" and they all appear there.
6:40pm: Let's start! First, I need to grab sultan's kernel. OK, "git clone", let's do it!
6:41pm: "Git is not installed". These errors freak me out, but at least this one is minor, lol. OK: step zero, install git.
6:42pm: THE COMMAND WORKED! First success. But, wow, the kernel is a huge download (300MB+). Damn, wish I started this earlier in the background.
6:44pm: I wonder if I can start installing the other things, too. But, how? Can I open another terminal window?
6:45pm: Yes, you can open another terminal window and even a tab. But, should I install other things? Might that interfere with "git clone"? Why risk it? I mean, it took two hours to get just here...
6:46pm: Throwing caution to the wind. Opening TWO terminal windows and starting apt-get with the other stuff.
6:50pm: No errors so far...
6:55pm: woot! Everything downloaded, nice, nice. OK, the last thing: those toolchains. What even is a toolchain?
6:56pm: OK, a toolchain is basically like a list of directories and their location? Or something? It's like a default variable location "list" or something. Hmm...OK, Phoenix used gcc 4.8, so that's what we'll do!
6:58pm: But, wait, the instructions at the gcc toolchain page say I need the "Android GCC repository" and even more dependencies. But, the guide doesn't mention any of that. Is this specific to the Google one? Looks like more downloading...
6:59pm: Err, hold on. I don't want to BUILD the toolchain. I just want it cloned to my system....I don't need to build the toolchain, right? OK, let's just get the gcc repo first and then we'll see.
7:05pm: Ugh, another huge download. I'm down to 180MB of free space! What? How did I use 12GB already?
7:06pm: Oh, the HDD is only 9.6GB. I guess formatting takes away some of it and Ubuntu's install, too. OK, we'll resize the partition and call it night. To be continued later...

---

A brief update, as I'm too tired to annotate everything today, haha. The reason the guide uses Doom's toolchains is because they're prebuilt. So, I guess, we'll use those. I'm creating the updated dwc3_otg.c from all the patches, but the hunks are failing after the first patch. Will troubleshoot today by looking at the reject file and see what's being moved around.
EDIT: OK, I actually just opened the patch files. Looks like I just need the latest one to apply to sollapse's original patch. Patches 1/2 are almost identical (and sans full overhaul). Patch 3 is superseded by patch 4. So, just patch 4 is the one you need. Huh. Let's do it! ;D
This guide is great for understanding patch files.

---

sollapse said:
Wow, I've completely abandoned this hack since it's worked well enough for me . Also haven't had much time due to work and other necessities. Thanks for the patches @Phoenix Wright for cleaning up this hack! This should be a standard addition to all future Android kernels.
Click to expand...
Click to collapse
thanks for your work, it's awesome feature
is there some solution without a kernel compiling ? some custom rom or kernel image

---

stadnyuk said:
thanks for your work, it's awesome feature
is there some solution without a kernel compiling ? some custom rom or kernel image
Click to expand...
Click to collapse
Its already there in my kernel called lightning kernel check tht sig for the link and if you are on cm then there is another thread in original android dev section

---

nikhil18 said:
Its already there in my kernel called lightning kernel check tht sig for the link and if you are on cm then there is another thread in original android dev section
Click to expand...
Click to collapse
Thank you, I'll check it. I've installed sultanxda ROM with hope for future kernel updates, but there is some bugs and I think to return to stock CM

---

nikhil18 said:
Its already there in my kernel called lightning kernel check tht sig for the link and if you are on cm then there is another thread in original android dev section
Click to expand...
Click to collapse
Hi again, I'm stuck with lightning kernel(((
Can't flash it. I'm starting to think I'm completely noon.
Flashing over night build of CM12 the cm version of kernel(V15)
Wipe, flash, wipe
The result - stuck on one plus logo
Flashing again sultanxda ROM, wipe, kernel, gapps
The result - boot loop
Where is the problem? What I'm doing wrong?
Now I'm on a last night build, am I right that I need V15 cm version?
Thank you for helping
PS: I've realized I was flashing cm13 kernel version with cm12 ROM, so flashed sultanxda 12, v33 kernel version - loop boot